This invention relates to an assembly for resiliently and releasably mounting the free end of a tiltable operator's platform to the frame of an earthmoving vehicle or the like.
Operator's cabs of earthmoving vehicles are often pivotally mounted to the frame of the vehicle to facilitate raising the cab from a substantially horizontal operating position in which it overlies vehicle components to a tilted maintenance position in which the vehicle components are exposed for maintenance work and repair. Tiltable cabs are typically secured at one end thereof to the frame by pivot means. The operator's cab is supported adjacent the other end thereof by releasable connectors.
The releasable connectors are conventionally provided with some means to hold the cab to the frame to prevent separation of the cab from the frame at the free end thereof when the vehicle is being operated and tilting is to be prevented. On the other hand, it is desirable to provide means to facilitate quick and easy release of the free end of the cab from the frame when tilting is desired and quick and secure mounting in the operating position when repairs are completed. It is also important that the cab be resiliently mounted to the frame both at the pivotal mounts and the releasable mounts to isolate the cab from vibrations generated in the frame during vehicle operation.
Various types of mounting apparatus are known which achieve some, but not all, of the desired mounting characteristics noted above. A resilient mount is shown in U.S. Pat. No. 3,847,492 of Kennicutt et al issued Nov. 12, 1974, to Caterpillar Tractor Co., the assignee of the present invention, in which a first connector attached to the cab is resiliently supported on a resilient bushing surrounding a bolt extending through a second connector attached to the frame. In U.S. Pat. No. 3,578,377 of Babbitt, Jr., et al, issued May 11, 1971, to the assignee of the present invention, a pivotally mounted frame with a releasable mount at the free end of the cab is shown, but no means is provided for isolating the cab from frame vibrations. In U.S. Pat. No. 3,203,728 of Wood issued Aug. 31, 1965, to Concrete-Steel Corporation, the end of a first connector is resiliently supported within a resilient boot combined between a pair of rigid semicylindrical connector sections attached to the frame, and a bolt extending through the cylindrical sections and the first connector prevents separation thereof. The bolt is apparently readily removable, but relative movement between the rigid end of the first connector and the resilient boot, detrimental to the resilient boot material, is permitted. Further, accurate vertical alignment between the cylindrical section and the first connector is needed for mating engagement and insertion of the bolt. Moreover, the bolt is completely removed from both connectors to allow separation and, when removed, may be misplaced or lost.
A different type of mount is shown in U.S. Pat. 3,667,566 issued June 6, 1972, to Hopkins, which is readily releasable, and in which the latch member is carried by one of the connectors. However, the latch member securing the two connectors together apparently supports the weight of the cab, and a complicated hydraulic-powered cylinder and piston assembly is thereby needed for disconnection. Further, no means are provided for isolating the cab from frame vibrations.